The Supreme Court reversed the conviction by ruling that the film was not obscene and so was constitutionally protected. However, the Court could not agree as to a rationale, yielding four different opinions from the majority. No opinion, including the two dissenting ones, had the support of more than two justices. The decision was announced by William J. Brennan, but his opinion was joined only by Justice Arthur Goldberg.

Justice Hugo Black, joined by Justice William O. Douglas, reiterated his well-known view that the First Amendment does not permit censorship of any kind. Chief Justice Earl Warren, in dissent, decried the confused state of the Court's obscenity jurisprudence and argued that Ohio's action was consistent with the Court's decision in Roth v. United States and furthered important state interests. Justice John Marshall Harlan II also dissented; he believed that states should have "wide, but not federally unrestricted" power to ban obscene films.

The most famous opinion from Jacobellis, however, was Justice Potter Stewart's concurrence, holding that the Constitution protected all obscenity except "hard-core pornography." Stewart wrote, "I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description; and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that."

The Court's obscenity jurisprudence would remain fragmented until 1973's Miller v. California. Many legal observers[who?] feel that after Miller, it remained confusing and vague. What is obscene in one place can be completely legal in another.